Designing the Task Features
When a colleague asks you to write a program to calculate running totals, is that enough information to code the operation and produce what he's asking for? Unless you're a mind reader, the answer is probably “No.” You need to fine-tune the definition of the operation before you can produce a meaningful result.
That's what you're going to do here—narrow down the operation of calculating running totals to just a few scenarios that a task can handle efficiently across a wide variety of data sources.
Assumptions: They Are Necessary
You know what they say happens when you assume that something is true? (If you don't know, you'll have to look it up as I cannot spell it out here. This is a family-friendly technical book.) ...